The goals of a radiology department include accurate diagnosis, rapid throughput of patients, timely reporting, and efficient retrieval of patients' radiologic examinations. Achieving these goals using the current film-based operation system is difficult, especially in a large medical center. The long-term objective of this program is to implement Picture Archiving and Communication System (PACS) in radiology with the hypothesis that the conventional film-based operation can be replaced by a digital- based PACS. Our department has been involved in PACS research and development for more than six years. Two years ago we successfully implemented two PACS prototypes in pediatric radiology and in the coronary care unit. Both systems have been in clinical use since March 1987 and they are being used daily. In order to test the hypothesis further, we propose to research and develop five PACS modules in our department during the next five years: three in intensive care units, one in neuroradiology, and one in chest radiology. The clinical loads of these five specialties represent about 35% of the examination procedures in our department. Successful implementation of these five PACS modules in the clinical environment, along with the existing pediatric radiology PACS will demonstrate the feasibility of PACS in radiology and validate the hypothesis. A successful research and development program in PACS will revolutionalize the practice of radiology and improve future health care delivery.